A cleaning tool is provided. More particularly, it is a cleaning tool for a pipe, the cleaning tool being moved internally in the pipe while rotating about substantially the centre axis of the pipe, and the cleaning tool being provided with a leading cleaning body at its free end portion, and there being arranged, close behind the free end portion, a tool support which is arranged to bear on the internal jacket surface of the pipe.
In the further description the cleaning of a pipe with deposits is taken as a basis, as such an operation adequately accentuates the advantageous features of the cleaning tool. However, the area of application of the cleaning tool is in no way limited to such work, as it will be usable for a number of operations in which a pipe or borehole is to be cleaned or extended and in which a so-called “pilot hole” is present.
During the operation of pipe facilities of different kinds it is well known that over time deposits may build up on the internal jacket surface of the pipe. This is particularly unfortunate in the case of long pipes to which access is difficult and in which chemical cleaning methods are not very effective.
Norwegian patent 320906 discloses a tool which by rotating tilted brushes in a pipe causes the brushes to be imparted an axial, oscillating movement relative to the pipe wall. U.S. Pat. No. 20255009 deals with cleaning bodies which are arranged to be flung out against the pipe wall by means of centrifugal force.
It is known to use a cleaning tool provided with a cleaning body for cleaning a pipe at its free end portion. The cleaning tool is moved along the pipe while being rotated about the longitudinal axis of the pipe. Cleaning tools which are provided with rotatable cleaning bodies have turned out to be effective, the cleaning bodies breaking up deposits when rolling against the internal jacket surface of the pipe. Norwegian patent 324515 and U.S. Pat. No. 2,150,806 disclose cleaning tools of this kind.
To reduce the risk of a cleaning tool sticking in the pipe, among other things, the external work diameter of cleaning bodies is somewhat smaller than the diameter of the internal jacket surface of the pipe. Experience has proved that because of uneven deposit thickness, for example, the cleaning tool may be moved out somewhat in a radial direction from the longitudinal axis of the pipe, whereby a helical opening is formed within the pipe.
During subsequent work in the pipe the somewhat helical opening within the pipe may cause tools to get stuck.
It is known to provide the cleaning tool with a tool support close behind the free end portion to counteract the formation of a helical opening. The tool support is arranged to bear on the internal jacket surface of the pipe.
Prior art tool supports are typically formed with sliding bodies, possibly with a scraping blade which bears on the internal jacket surface. The scraping blade is arranged to further clean deposits from the internal jacket surface of the pipe. Prior art tool supports have turned out to be relatively ineffective.
The invention has for its object to remedy or reduce at least one of the drawbacks of the prior art.
The object is achieved according to the invention through the features which are specified in the description below and in the claims that follow.